Spanish rescuers are trying to rush months-worth of tunnel drilling work into mere days as their efforts to save a missing two-year-old boy from a deep hole intensify.

Rescue workers found some of the boy’s hair in a narrow borehole close to where he went missing near Totalan in Malaga, and DNA tests confirmed the hair is his.

Government representative Maria Gamez said the hair samples give rescuers “scientific evidence that the minor is there,” El Pais reports.

The borehole is over 100 meters (328 feet) deep and, with a circumference less than 25 centimeters, is too small for adults to get down, so workers are drilling two different tunnels in a bid to access the crevice.

Rosello went missing on Sunday after he wandered away from his parents who were setting up an outdoor lunch at a relative’s property near Totalan. A bag of sweets he had been carrying has already been found inside the hole.

“It feels like we have been waiting for months,” Julen’s father Jose Rosello told reporters Thursday. “We are not going to give up... We have the hope that an angel is going to show up for my son to come out alive.”

Rescue workers have been unable to get past a blockage of stones and dirt some 73 meters down the shaft. Although over 100 people are working on the project, progress is slow as the area’s terrain is prone to landslides. It is expected they will reach the deepest part of the shaft by creating a side tunnel within 48 hours – however, heavy rain is expected on Friday and Saturday, adding additional pressure to get the tunnel completed.